Installing 3rd Function Hydraulics - Electric over Hydaulic

[cowboy_79_1999]

It becomes a problem when you are using multiple valves in series without a power beyond circuit, (which the solenoid valves we are talking about do not have). You must have a relief valve in an open system. I believe most 3rd function valve add ons without their own relief rely on the relief in the loader valve. I know that is how my JD 3520 works.

 

[J_J]

You can get subplates with relief valve ports if desired.

https://www.google.com/url?sa=t&rct...9itX8rrF5DyMYsLnQ&sig2=WztfOj-ZrKAJACVIf1or4Q

Relief valve should not be a big problem anyway as you can add an external relief valve anywhere.

 

[cowboy_79_1999]

Not just anywhere, In an open system, it must be upstream of the valve.

 

[J_J]

But of course.

Just about all valves in an open center hyd system will have a relief valve, and the 3rd function valves and manifold valves can have a relief valve, and it is before any solenoid valve.

Closed center valves do not need a relief valve as the relief valve is located close by the pump, and each valve in the parrallel hyd path could be the first valve.

 

[J_J]

cowboy_79_1999

It becomes a problem when you are using multiple valves in series without a power beyond circuit, (which the solenoid valves we are talking about do not have).

Just about all subplates can handle about 3000 to 5000 psi, and are considered PB.

Although they call the T port a tank port, it also feeds the fluid to the next valve.

A subplate will have 4 hose ports, P,T,A,B.

It could also have a relief port and a hyd gage port.

 

[cowboy_79_1999]

JJ, I'm not trying to be argumentative on this subject, I'm simply trying to offer my knowledge gained on this very subject while researching adding a solenoid valve to my own compact tractor.

That being said, I must disagree with you that these valve bases are considered pb. On an open center system, Open or tandem center solenoid valves must be used to allow "pump" flow to the tank port when the valve is in the neutral position. To my knowledge this is not true power beyond. Motor valves in neutral position, block the p port and connect a,b,t to allow a motor wind down. Blocking p will load the pump until the relief kicks in as well as blocking flow to downstream valves i.e. 3pt hitch, so they should not be used in this application. Multiple valves must be plumbed in series and series bases are available, but my original point is that each solenoid valve added will reduce flow to, and cause a pressure drop to the next valve in the series since the oil must flow through each valve before traveling to the next. There will also be a flow restriction and pressure drop associated with the base itself. On relatively small hydraulic systems found on our compact tractors that were not originally engineered for solenoid valves, these losses could add up quick and reduce the lift capability and speed of each successive valve and ultimately the 3pt hitch. Flow restrictions also create additional heat which could cause more problems on smaller systems that may not have sufficient oil cooling.

I'm confident that for my system, adding one tandem center solenoid valve will not cause any significant problems, as others have successfully added 3rd function solenoid valves on their tractors with no problems. I had considered adding 3 valves until I did some research and asked a local hydraulic shop their thoughts. I've concluded that I'm better off with one solenoid valve and possibly adding a diverter valve to split the function to 3rd and 4th QD pairs.

 

[J_J]

For the sake of argument, I hope you don't believe everything you said in your post.

You said, [ block the p port ] You do not ever block the P port using an OC hyd system.

The T port is not really a tank port unless the valve assembly is used as the last valve in the system before the tank.

When the the solenoid assembly including subplate is in neutral, whether it is a cyl valve or a motor valve, the fluid is flowing from P to T. Most definitely a PB port of at least 3000 psi.

You do not stop the flow in an open center hyd system, as the fluid is moving all the time either going to a hyd component or flowing to the next valve.

PB is just the ability to handle high pressure.

There is not a significant pressure loss by connecting valves in series. It is done all the time.

When the valve is activated, fluid is redirected to the A and B ports, the used fluid is flowing out through the T port. Same goes for the hyd motor, as you push fluid through the IN port of the hyd motor, the motor is expelling fluid through the T port. This fluid is going to the next valve.

A lever hyd valve has a dedicated low pressure port for the expended fluid. T port..

If you still think I am wrong, then so be it.

 

[cowboy_79_1999]

Ok, since I have 5 min for the sake of argument.

For the sake of argument, I hope you don't believe everything you said in your post.

I do in fact believe everything I said in my post.

You said, [ block the p port ] You do not ever block the P port using an OC hyd system.

Just as I said: "Blocking p will load the pump until the relief kicks in as well as blocking flow to downstream valves i.e. 3pt hitch, so they should not be used in this application."

The T port is not really a tank port unless the valve assembly is used as the last valve in the system before the tank.

It is also not necessarily a PB port .

When the the solenoid assembly including subplate is in neutral, whether it is a cyl valve or a motor valve, the fluid is flowing from P to T. Most definitely a PB port of at least 3000 psi.

Many solenoid valves have a T port that in fact is NOT rated for full system pressure

You do not stop the flow in an open center hyd system, as the fluid is moving all the time either going to a hyd component or flowing to the next valve.

Agreed!

PB is just the ability to handle high pressure.

I think we disagree on the definition of Power Beyond. So be it.

There is not a significant pressure loss by connecting valves in series. It is done all the time.

There is always some pressure and flow loss with anything added to an open hydraulic system because everything is in series. This includes hoses/fittings/valves/etc. Hydraulic pumps are generally sized for the required gpm and pressure to the last valve in the system after accounting for all losses, and therefore adding something in between will in some way reduce the supply downstream. Granted that most systems can probably handle some additions, as they may not be "significant," but I would encourage folks to do the research before adding to the factory hydraulic system on a CUT. Especially with multiple solenoid valves as they can vary greatly in their gpm and pressure capability.

When the valve is activated, fluid is redirected to the A and B ports, the used fluid is flowing out through the T port. Same goes for the hyd motor, as you push fluid through the IN port of the hyd motor, the motor is expelling fluid through the T port. This fluid is going to the next valve.

Agreed. And now this fluid is "used" and in fact is not Power Beyond.

A lever hyd valve has a dedicated low pressure port for the expended fluid. T port..

True for most, but not all.

If you still think I am wrong, then so be it.

Honestly, Its not that I'm trying to prove you wrong, but some of your points can be misleading. For example your advice to Kevincook, to "Just go to Surplus and choose your valves, and a sub plate that will accommodate the number of valves you want." This could lead someone to purchase a parallel multiple valve sub plate with open center valves and motor spool valves. When in fact he would need a series sub plate with tandem center valves to accomplish his goals.

I encourage anyone attempting to DIY additional hydraulics on their CUT's to do plenty of research and if need be seek the advice of a professional hydraulic shop or even your local tractor dealer before starting. My local shop was very helpful in guiding my decision to add a single Electric over Hydraulic valve on my tractor.

Good day,

 

[J_J]

What would you do with all the 3rd functions multi-valves on all those tractor, and other machinery, recall them for modification based on what someone told you.

Would you even know which subplates were series, parallel, or series-parallel?

In using the subplates, do you even know which ones to use, and which valves to install in position 1,2,3.

Do you know which position on the subplate has priority?

Do you know how many valves can be operated at the same time on a 3 valve subplate? Maybe your expert at the hyd shop you visited will know.

Would you really fix something not broke.

Keep on thinking about the pressure losses caused by all those elbows, reducers, hoses, ports not matched up to specs if you think it will help you.

Critique me if you will, I don't mind being wrong.

My suggestions and recommendations are just that, offered without any return.

I would like to think I am correct in my thinking, but fill free to poke and jab.

If you don't like things I say or I offend your intelligence, just put me on your ignore list.

 

[matoyan]

I appreciate all your help J.J. Thank you for being there for me and others.

 

[matoyan]

Hi,

I am installing my 3rd function this weekend and I wanted to know if I could hook up the new hoses to a snow plow that has SA cylinder? It's an old plow that has two cylinders, one on each end of the plow or do I have to install a DA cylinder? We have another snow storm due to hit us on Monday and it would make life easier for me to move the angle of the plow using hydraulics instead of physically man handling it. Thanks.

 

[aczlan]

Hi,

I am installing my 3rd function this weekend and I wanted to know if I could hook up the new hoses to a snow plow that has SA cylinder? It's an old plow that has two cylinders, one on each end of the plow or do I have to install a DA cylinder? We have another snow storm due to hit us on Monday and it would make life easier for me to move the angle of the plow using hydraulics instead of physically man handling it. Thanks.

The two cylinders connected to the plow act as one DA cylinder. Hook one DA hose to each cylinder and you should be good to go.
If using your loader valve's bucket curl/dump circuit, you might have to play with how far over it needs to go as the "regen" mode may not work.


Aaron Z

 

[matoyan]

I finally got my 3rd function installed today. Thanks to Irsmun and JJ for all their help and guidance. It really wasn't as hard as I thought. The most difficult part was stopping all of the hydraulic leaks from the connections. I still have one tiny leak, but it's really hard to get to. I'm going to wait until the weather warms up a bit. My fingers were numb from the cold weather and the snow on the ground. I hooked up my snow plow and it works great. I just need to order a grapple now. I connected the switch to my dash and when I upgrade to a joystick, I'll move it. I just have to get wire protectors to make sure nothing happens to them.

 

[AaronS]

Thanks so much for such a great and detailed write-up! I'd like to do this to my L3400 to angle a snow-plow and hopefully one day power a grapple, and now I feel that I can do this myself.

 

[irsmun]

matoyan, good job. I had a heck of job getting all the leaks sealed. The guy a discounthydraulics.com told me I did not need any type of sealer unless I was taking them on and off, on and off. I did not find that to be true. I used high pressure pipe sealant and it worked great.

I have had mine on for a few months now and my only disappointment is that I cannot do all the functions (lift, curl, open or close) at the same time. That is something I wanted to do and why I went with this set up. Its not a problem with the design as much as it is tractor hydraulic pumps in general. 11gpm's at a few hundred rpms doesn't give you enough flow to share. You'd have to rev it to PTO speed to do it and I don't get that aggressive using the foot throttle usually.

I am glad this thread is helping. I drove JJ crazy before I took the plunge. It is getting a little crowded though with other chatter. Oh well, all the info is at the front.

 

[J_J]

Do you understand why you can not use lift, curl, and grapple at the same time using the 3rd function valve?

 

[irsmun]

I do understand. I need more gpm's so there is enough hydraulic fluid and pressure to share. When I have it reved up at high rpms I can do multi functions as long as I'm not 100% on any one. But most of the time I'm operating the grapple with low to medium rpms with the foot peddle. Like I said, I don't slam it down all the way to get 2100 or so. Its not practical to set the hand throttle since you are stopping and starting a lot using the grapple.

I'm sure it also has something to do with the loader control valve and its rating. When I'm not feeding it its max (12gpm?) then the functionality of the valve has different properties with lower hydraulic flow. I guess its like if you used a 50 gpm valve with a 12 gpm pump. I see why you recommend people go with the diverter. For most people, they will get the same functionality...at least with a grapple.

It was one of my basic misunderstandings from the beginning when I was going over this with you. I thought 11 gpms and 3000psi was a constant. I did not realize that was only at max engine rpms. How nice it would be for the pump to be operating at max without regard to the engine rpms. Then you could idle and do all your hydraulic work...but the power would still have to come from somewhere. You would need a super efficient pump that could put that out at 800 rpms.

 

[J_J]

Some people don't understand the flow path and GPM's when trying to use more than one spool or valve at the same time.

On a tractor, it is rare that you need to use more than one spool or valve at the same time. A few seconds will not destroy your operation when selecting different spools or valves. .

Even the guys at WR Long do not understand the flow through the 3rd function. What they say is that when using total flow to the cyl, that there is flow from the PB port going through the 3rd function. There is no flow to the PB when full cyl flow is being used. When the relief is activated, the flow is also diverted to tank.

I am not sure he realizes that if all pump flow is going into a cyl, there is flow coming out the cyl, but, it is going to tank, and nothing goes downstream until you let off the lever, and then the pump flow now passes through the PB port for downstream use.

It doesn't take but a few seconds to fill a cyl and you are ready for the next spool operation.

When using a solenoid valve with subplate, all flow exits the T port including the cyl flow and pump flow.

Downstream valves, when fully activated, will affect all valves up stream by the back pressure generated, as that fluid is competing with the pump flow.

If you could use all spools in parallel, what would happen would be that the hyd component requiring the least pressure would operate first and when that component is satisfied, the next hyd component will operate. If more that one hyd component is equal, then the flow will divide.

Loader valves with a parrallel setup can use two spools at the same time, and the flow is divided.

If you half loader spool, you can also use the 3rd function at the same time, such as loader lift and grapple.

 

[matoyan]

Hi J_J

I bought a brantly backhoe for my John deere 750 and I wanted to know what's the best way to get hydraulics to the backhoe? I have a 3rd function installed already for the grapple and the snow plow. Thanks.

 

[J_J]

Is your tractor open center hyd?

Do you have any hyd at the back now except for the 3pt?

Do you have a hose going to the back for the 3pt?

You could add a remote to the back with PB and use the PB from the remote valve to power the BH

It might be as simple as adding the valve in series with the 3rd function valve and putting a QD on the remote valve PB line. Your BH would then plug into the PB QD.

When not using the BH, the QD would connect to the 3pt.

Show some pictures of the right side and back side.